Watch-hand



(No Model.)

D. H. CHURCH. WATCH HAND. N0.605;269. Patented June 7,1898.

\A/iT'NEEEEEi INVENTU M4 @I N M %J W I mZ UNITED STATES TENT ClementDUANE H. CHURCH, OF NEWTON, MASSACHUSETTS.

WATCH-HAND.-

SPLEOIFIGATION forming part of Letters Patent No. 605,269, dated June 7,1898.

A li ti fil d December 1'7, 1895. Serial No. 572,392. (No model.)

' of Massachusetts, have invented certain new and useful Improvements inWatch-Hands and Supporting MechanismTherefor, of which the following isa specification.

This invention relates to the attachment of watch-hands to thecannon-pinion and hourwheel of-a watch-movement; and it has for itsobject to provide simple andefiicient means for securing the hands insuch manner that they can be applied and removed without liability 'ofinjury to any of the delicate parts of the watch-movement and when inplace will be held positively without liability of either handprojecting into the path of the other.

To these ends the invention consists in the improvements which I willnow proceed to describe and claim.

Of the accompanying drawings, forming a part of this specification,Figure 1 represents a side view of a center-staff, showing in sectionthereon the cannon-pinion, hour-wheel, and hands. Fig. 2 represents asection on line 2 2 of Fig. 1. Fig. 3 represents a side view of theminute-hand. Fig. 4; represents an edge view of the socket of thehour-hand.

The same letters of reference indicate the same parts in all thefigures.

In the drawings, a represents the cannonpinion proper, and a the hub orsleeve portion thereof, having bearings c a for the hour-wheel h.Between said bearings the portion a is provided with longitudinal slots(L13, between which are left longitudinal sections a These sections arecurved inwardly and present curved bearings to the centerstalf b. Thecenter-staff is provided with a peripheral recess along that port-ionWhich coincides with the sections a, said recess pre senting a gradualback taper from its deepest portion to a point near the outer end of thestaff.

Although I have thus particularly described the construction of thecannon-pinion and its engagement with the center-stafi, I do not wish tobe understood as limiting myself thereto, as the cannon-pinion andcenter-staff may be constructed in any other suitable manner to effect asuitable engagement between the two.

The cannon-pinion is extended outwardly beyond the outer end of thecenter-staff and provided with an internal screw-thread, said threadsurrounding a chamber or socket at the outer end of the center-staff.The minutehand on is secured to the cannon-pinion by a screw 2', formedto engage the internal thread in the extension of the cannon-pinion.Said screw is preferably secured permanently to the minute-hand and maybe either made integral therewith or in a separate piece, staked orotherwise secured in a socket formed in the minute hand. By thusattaching the minute-hand to the cannon-pinion I do away with thepressure required in forcing the minute-hand to place on its bearing onthe cannon-pinion when the minute-hand has a socket pressed intofrictional engagement with the cannon-pinion, as heretofore, suchpressure being liable to injure the jewel on I which the inner end ofthe center-staff has its hearing. I also insure the firm seating of theminute-hand upon the outer end of the cannon-pinion, so that theposition of the minutehand is positively assured and its liability ofbeing deflected so as to enter the path of the hour-hand is prevented.The screw connection between the minute-hand and the cannonpinion alsoenables the minute-hand to be removed simply by the use of ascrew-driver, no special tool being required and no liability incurredof cracking the dial by the prying operation usually required inremoving the minute-hand.

My improvements further include as a means for securing the hour-hand 0a backtapered seat 0 on the hub of the hour-wheel, said seat surroundingthe outer portion of the cannon-pinion, and an elastic back-taperedsocket o ,form ed on the hour-hand,said socket being transversely cut ato and made of elastic construction, so that it embraces and closely fitsthe seat 0. The back taper of the seat 0 and socket 0 is such that whenthe socket is sprung onto said seat it cannot be accidentallyremoved,the effect of the natural contraction of the socket on theback-tapered seat being to press the socket downwardly against theshoulder 0 ,Wl1lCl1 limits its downward movement. Hence the hour-handmay be said to be automatically seated or pressed downwardly and heldout of the path of the minute-hand. The elastic socket enables thehour-hand to be readily turned on the-hub of the hour-wheel in adjustingits position, the socket being readily enlarged by forcing ascrew-driver into its slot or opening, the resulting contraction insnring the proper bearing of the hour-hand against the shoulder, so thatthere is no liability of lateral displacement of the hour-hand as aresult of its adjustment.

Witnesses:

O. F. BROWN, A. D. HARRISON.

